Final answer:
The term 'Data's Day of Reckoning' in Data Science & Ethics signifies a critical moment for evaluating the ethical use of data, focusing on privacy, consent, and transparency.
Step-by-step explanation:
When the authors of Data Science & Ethics refer to Data's Day of Reckoning, they are speaking about a turning point or a critical moment when the practices and consequences of data collection and analysis must be scrutinized and re-evaluated. This term indicates a period where society as a whole must reflect on the ethical implications of how data is used, with an emphasis on privacy, consent, and transparency. The phrase suggests that there will be a time when individuals and organizations will have to face the consequences of their actions in data science, particularly if they have neglected the ethical dimensions of their work.